Surgical stapler with timer and feedback display

ABSTRACT

A surgical apparatus has a clamp and a stapling mechanism. The clamp has a first jaw and a second jaw to clamp on a body tissue at a desired location for a stapling operation. The stapling mechanism is controlled by a trigger handle or a switch assembly. The surgical apparatus has a controller for providing a delay between clamping and actuating of the firing mechanism of the stapling mechanism. The delay provides for a desired amount of time for tissue compression producing a more uniform staple formation. The surgical apparatus also has an indicator. The indicator provides feedback about the status of the stapling mechanism and also displays a time of tissue compression by the clamp.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 13/052,871, filed on Mar. 21, 2011, which is acontinuation of U.S. patent application Ser. No. 12/247,733, filed onOct. 8, 2008, which is a continuation of U.S. patent application Ser.No. 11/446,283, filed on Jun. 2, 2006, now U.S. Pat. No. 7,461,767,which claims priority to U.S. Provisional Patent Application Ser. No.60/687,406, filed Jun. 3, 2005 and to U.S. Provisional PatentApplication Ser. No. 60/687,244, filed on Jun. 3, 2005, the entirecontents of all of which are incorporated by reference herein.

This patent application is also a continuation-in-part of U.S. patentapplication Ser. No. 13/277,544, filed on Oct. 20, 2011, which is acontinuation of U.S. patent application Ser. No. 12/959,421, filed onDec. 3, 2010, which is a continuation of U.S. patent application Ser.No. 12/645,144, filed on Dec. 22, 2009, now U.S. Pat. No. 7,845,534,which is a continuation of U.S. patent application Ser. No. 12/108,916,filed on Apr. 24, 2008, now abandoned, which is a divisional of U.S.patent application Ser. No. 11/446,282, filed on Jun. 2, 2006, now U.S.Pat. No. 7,464,847, which claims priority to U.S. Provisional PatentApplication Ser. No. 60/687,406, filed Jun. 3, 2005 and to U.S.Provisional Patent Application Ser. No. 60/687,244, filed on Jun. 3,2005, the entire contents of all of which are incorporated by referenceherein.

BACKGROUND

1. Technical Field

The present disclosure relates to surgical instruments. Moreparticularly, the present disclosure relates to a surgical staplingdevice that has a feedback and a timer device. Even more particularly,the present disclosure relates to a surgical stapling device that has acontroller to modulate one or more parameters of the surgical staplingdevice and to provide for compression of tissue. Still even moreparticularly, the present disclosure relates to a surgical staplingdevice that may also include a sensory indicator (i.e., visual, audible,tactile) which determines position, time, or other valuable userfeedback.

2. Background of the Related Art

Once under pressure from a jawed structure, such as a clamping device,of a surgical stapler, the body tissue will slowly compress. Compressionby a clamping device reduces the amount of blood and fluid to theclamped tissue. Without such compression, an uncompressed body tissueremains thicker whereas the compressed body tissue would be thinner, andmore compact. Compressing the tissue also causes blood and other fluidto generally traverse from the high pressure or compressed area toanother low pressure or adjacent area.

Once released, the fluid due to the visco-elastic property of the tissuewill return from the adjacent area to the previously compressed tissue.Some current surgical stapling devices initially compress tissue priorto the introduction of the staple into the body tissue. The amount oftime tissue is compressed is currently left to the discretion of thesurgeon. The surgeon manually controls the amount of time that thetissue is compressed prior to firing the staples into tissue. It wouldbe therefore desirable to have a surgical stapling device thatconsistently fires staples after a predetermined amount of compression.

SUMMARY

According to a first embodiment of the present disclosure, there isprovided a surgical stapler that has a handle assembly including astationary handle and a pivotable handle mounted for manipulationthrough an actuating stroke. In another embodiment, the stapler may havea trigger that is operable to manipulate a cam member through theactuating stroke. The stapler also has an elongated body extendingdistally from the handle assembly and defining a longitudinal axis and astaple cartridge supported adjacent the distal end of the elongated bodyand containing a plurality of staples.

The stapler further has an anvil pivotally mounted in relation to thecartridge adjacent the distal end of the elongated body with the anvilhaving a fastener forming surface thereon and being mounted for pivotalmovement in relation to the cartridge between an open position having adistal end spaced from the staple cartridge and a closed position inclose cooperative alignment with the staple cartridge. The stapler alsohas an actuation sled supported within the cartridge. The actuation sledmoves to urge the plurality of staples from the cartridge.

The stapler further has a drive assembly including a body having aworking end and a cam member supported on the working end. The cammember is positioned to translate relative to the anvil to maintain theanvil in the closed position during firing of the stapler. The triggeror pivotable handle is operatively connected to the drive assembly suchthat manipulation of the pivotable handle through its actuating strokeeffects translation of the cam member relative to the anvil. The stapleralso has a channel for supporting the staple cartridge and a controllerconfigured to control the actuation sled supported within the cartridge.The controller delays movement of the actuation sled to urge theplurality of staples from the cartridge for a predetermined time periodwhen the anvil is in the closed position and in cooperative alignmentwith the staple cartridge.

According to another aspect of the present disclosure, the surgicalstapler has a handle assembly including a stationary handle and atrigger configured to manipulate a cam member through an actuatingstroke. The stapler also has an elongated body extending distally fromthe handle assembly and defining a longitudinal axis and a staplecartridge supported adjacent the distal end of the elongated body withstaples. The stapler further has an anvil pivotally mounted in relationto the cartridge adjacent the distal end of the elongated body. Theanvil has a fastener forming surface thereon and is mounted for pivotalmovement in relation to the cartridge between an open position having adistal end spaced from the staple cartridge and a closed position inclose cooperative alignment with the staple cartridge.

The stapler also has an actuation sled supported within the cartridge.The actuation sled moves to urge the staples from the cartridge. Thedrive assembly includes a body having a working end and a cam membersupported on the working end. The cam member is positioned to translaterelative to the anvil to maintain the anvil in the closed positionduring firing of the stapler.

The trigger is connected to the drive assembly such that manipulation ofthe trigger through its actuating stroke effects translation of the cammember relative to the anvil. The stapler also has a channel forsupporting the staple cartridge. The stapler also has a controller. Thecontroller is configured to control the actuation sled supported withinthe cartridge. The controller delays the actuation sled's movement tourge the plurality of staples from the cartridge for a predeterminedtime period when the anvil is in the closed position and in cooperativealignment with the staple cartridge. The surgical stapler also has anindicator connected to the controller. The controller controls theindicator to provide an indication when the predetermined time period isreached.

According to another embodiment of the present disclosure, there isprovided a method for stapling tissue. The method includes the steps oflocating tissue between a staple cartridge and an anvil and compressingtissue between the staple cartridge and the anvil. The method also hasthe step of manipulating an actuator to fire staples from the staplescartridge. The actuator is configured to automatically delay firingstaples for a predetermined time period. The predetermined time periodis suitable in length to allow compression of the tissue for thepredetermined time period and to allow tissue to settle from a firstinitial state into a second compressed state. The method also has thesteps of urging staples from the staple cartridge through the tissue atthe elapse of the predetermined time period when the tissue is in thesecond compressed state.

According to another aspect of the present disclosure, the surgicalstapler has a controller to place a delay between actuation of thefiring mechanism component and actual firing of the staple.

According to another aspect of the present disclosure, the surgicalstapler has a control device that controls a stroke parameter, adistance parameter and/or a time parameter of a firing mechanismcomponent to increase a tissue compression time of the clamp.

According to still another aspect of the present disclosure, thesurgical stapler has a motor and a first switch. The first switch isconnected to a motor and delays the motor from actuating in order toachieve an amount of tissue compression by a clamp. The surgical staplermay have a second switch. The second switch senses another location of adrive screw and actuates a reverse function of the motor to return thedrive screw to an initial position.

According to still yet another aspect of the present disclosure, thesurgical stapler has an indicator that measure a distance traveled ofthe drive screw or a tissue compression time of the clamp.

According to still another aspect of the present disclosure, thesurgical stapler has a visual indicator that indicates a position of thefiring mechanism component or indicates a status condition of thesurgical stapling.

In another embodiment of the present disclosure, there is provided asurgical stapler. The stapler has a handle assembly including a triggerand a clamping device with a staple cartridge including a plurality ofstaples and an anvil having a fastener forming surface thereon. Thestapler has a controller configured to determine an occurrence ofclamping by the anvil and the staple cartridge. The controller controlsa firing of the plurality of staples from the staple cartridge. When thetrigger is actuated the controller delays firing of the plurality ofstaples from the staple cartridge to provide for a predetermined timeperiod of tissue compression of the tissue between the anvil and staplecartridge. The controller outputs a control signal to allow firing oncethe predetermined time period is reached.

According to one aspect of the present disclosure, a surgical stapler isprovided. The stapler includes a handle assembly, a clamping devicehaving a staple cartridge containing a plurality of staples and an anvilto compress tissue therebetween, a drive assembly at least partiallylocated within the handle and connected to the clamping device, a motoroperatively coupled to the drive assembly; and a controller operativelycoupled to the motor, the controller configured to control supply ofelectrical current to the motor at a first level in response to whichthe motor is configured to operate between first upper and loweroperational limit values, the controller is further configured tocontrol supply of electrical current to the motor at a second level inresponse to which the motor is configured to operate between secondupper and lower operational limit values.

The stapler according to the present disclosure may further comprise adriver circuit coupled to the motor and the controller, the drivercircuit configured to measure rotational speed of the motor.

The controller may be further configured to supply electrical current tothe motor at the second level in response to the rotational speed of themotor being lower than the first lower operational limit value andterminate supply of electrical current in response to the rotationalspeed of the motor being lower than the second lower operational limitvalue.

According to another aspect of the present disclosure, a surgicalstapler is disclosed. The stapler includes a handle assembly; a clampingdevice having a staple cartridge containing a plurality of staples andan anvil to compress tissue therebetween; a drive assembly at leastpartially located within the handle and connected to the clampingdevice; a motor operatively coupled to the drive assembly; a drivecircuit coupled to the motor and configured to measure at least oneoperational property thereof; and a controller operatively coupled tothe motor and the drive circuit, the controller configured to controlsupply of electrical current to the motor at a first level and tocontrol supply of electrical current to the motor at a second level inresponse to the at least one operational property being lower than thefirst lower operational limit value.

According to an additional aspect of the present disclosure, the drivecircuit is configured to control operation of the motor as the currentis supplied at the first level between a first upper operational limitvalue and the first lower operational limit value. The drive circuit isfurther configured to control operation of the motor as the current issupplied at the second level between a second upper operational limitand the second lower operational limit value.

According to an additional aspect of the present disclosure, thecontroller is further configured to terminate supply of electricalcurrent in response to the at least one operational property being lowerthan a second lower operational limit value.

According to another aspect of the present disclosure, wherein the atleast one operational property, the first upper and lower operationallimit values, and the second upper and lower operational limit valuescorrespond to a rotational speed of the motor. The second upper andlower operational limit values are lower than the first upper and lowerlimit values and the first level is lower than the second level.

According to a further aspect of the present disclosure, a method forcontrolling a surgical stapler is also disclosed. The method includessetting current supplied to a motor at a first level, the first levelassociated with first upper and lower operational limit values of themotor; measuring at least one operational property of the motor;increasing current supplied to the motor at the first level to a secondlevel in response to the at least one operational property of the motorbeing lower than the first lower operational limit value, the secondcurrent level associated with second upper and lower operational limitvalues of the motor; and terminating current supplied to the motor atthe second level in response to the at least one operational property ofthe motor being lower than the second lower operational limit value.

According to further aspects of the present disclosures, the first upperand lower operational limit values and the second upper and loweroperational limit values are rotational speed limit values, wherein thesecond upper and lower operational limit values are lower than the firstupper and lower limit values, further wherein the first level is lowerthan the second level.

DESCRIPTION OF THE DRAWINGS

Other and further objects, advantages and features of the presentdisclosure will be understood by reference to the followingspecification in conjunction with the accompanying drawings, in whichlike reference characters denote like elements of structure and:

FIG. 1 is a perspective view of a first embodiment of a surgical stapleraccording to the present disclosure;

FIG. 2 is a block diagram of a number of components of the surgicalstapler of FIG. 1 according to the present disclosure;

FIG. 2A is an exploded view of a channel of the surgical stapler of FIG.1 according to the present disclosure;

FIG. 2B is an exploded view of the staple cartridge, anvil and the drivesled of FIG. 1 according to the present disclosure;

FIG. 3 is a perspective view of another embodiment of the surgicalstapler of the present disclosure having a plurality of lights accordingto the present disclosure;

FIG. 4 is a perspective view of still another embodiment of the surgicalstapler with a linear indicator or display according to the presentdisclosure;

FIG. 5 is a perspective view of yet another embodiment of the surgicalstapler having a digital indicator or display according to the presentdisclosure;

FIG. 6 is a perspective view of still another embodiment of the surgicalstapler with an analog indicator or display according to the presentdisclosure;

FIG. 7 is a cross sectional view of the surgical stapler of FIG. 3 alongline 7-7 according to the present disclosure;

FIG. 8 is another cross sectional view of still another embodiment ofthe surgical stapler of the present disclosure along line 7-7 of FIG. 3with the stapler having a first switch and a second switch according tothe present disclosure;

FIG. 8A is another cross sectional view of another embodiment of thestapler of FIG. 8 having the first switch which engages a tab on thelever according to the present disclosure;

FIG. 8B is still another cross sectional view of yet another embodimentof the stapler of FIG. 8 having the first switch located distally on thelever according to the present disclosure;

FIG. 9 is another perspective view of still another embodiment of thesurgical stapler with an audible alarm according to the presentdisclosure;

FIG. 10 is still another perspective view of another embodiment of thesurgical stapler having the display showing an image according to thepresent disclosure;

FIG. 11 is a schematic/cross sectional view of a travel path of a drivemember through an endoscopic portion of the surgical stapler with aresistor strip according to the present disclosure;

FIG. 12 is a schematic of another embodiment of the surgical staplerhaving a non-contact sensor according to the present disclosure;

FIG. 13 is a schematic of another embodiment of the surgical stapleraccording to the present disclosure;

FIG. 14 is a flow chart of a method for controlling the surgical stapleraccording to the present disclosure; and

FIGS. 15-17 are plots of mechanical resistance, rotational speed, andcurrent applied to a motor of the surgical stapler as controlled by themethod of the present disclosure.

DETAILED DESCRIPTION

In the drawings and in the description which follows, the term“proximal”, as is traditional, will refer to the end of the apparatuswhich is closest to the operator, while the term “distal” will refer tothe end of the apparatus which is furthest from the operator.

The present disclosure can be used with any stapler device known in theart and is intended to encompass the same, and is intended to bediscussed in terms of both conventional and endoscopic procedures andapparatus. However, use herein of terms such as “endoscopic”,“endoscopically”, and “endoscopic portion”, among others, should not beconstrued to limit the present disclosure to an apparatus for use onlyin conjunction with an endoscopic tube. The apparatus of presentdisclosure may find use in procedures in these and other uses includingbut not limited to uses where access is limited to a small incision suchas arthroscopic and/or laparoscopic procedures, or other conventionalmedical procedures. The present mechanism may also be used with surgicalstapling devices that have independent or combined clamping and firingprocedures. The present disclosure may further be incorporated withsurgical stapling devices that have simultaneous or dependent clampingand firing mechanisms. The present disclosure is also intended to beused with such surgical stapling devices which have a discrete clampinggradient.

Referring now to the figures, wherein like reference numerals identifysimilar structural elements of the subject disclosure, there isillustrated in FIG. 1 a self-contained, powered surgical staplerconstructed in accordance with an embodiment of the subject disclosureand designated generally by reference numeral 10. The surgical stapler10 is generally intended to be disposable, however the disposablearrangement is non-limiting and other non-disposable arrangements may becontemplated and are within the scope of the present disclosure.

The surgical stapler 10 of the present disclosure (shown in aperspective view in FIG. 1 and described herein) includes a framegenerally represented by reference numeral 12 and handle generallyrepresented by reference numeral 14. The frame 12 defines a series ofinternal chambers or spaces for supporting various inter-cooperatingmechanical components of the surgical stapler 10 as well as a number ofstaples therein for the application to the body tissue.

The frame 12 supports a portion 16 or an extended tube-like portion. Theportion 16 is capable of being rotated and has a relatively narrowdiameter in a range of about 10 millimeters, and is for insertion into asmall opening or tube inserted into the body, such as in the abdominalcavity, or other similar body cavities. The portion 16 has alongitudinal axis and has a length appropriate for reaching theoperation site in the interior of the body. The surgical stapler 10 maybe used in conjunction with other instruments such as endoscopes orother such optical devices for visually examining the interior of thebody, for example, cameras by means of CCD devices, fiber optics orother optical or recording devices.

Generally, portion 16 of the surgical stapler 10 is inserted through thesmall opening or wound, and is manipulated to the operation site. Thepresent disclosure is intended to be used with any surgical staplerincluding but not limited to surgical staplers having simultaneousclamping and independent clamping.

Portion 16 has a fastening assembly generally represented by referencenumber 18 and cutting assembly (not shown) that is known in the art. Thefastening assembly 18 and the cutting assembly (not shown) are locatedin a housing 20 which carries a fastener and an optional cutter to theoperation site. The fastening assembly 18 in this particular embodimenthas a jaw or a staple cartridge 21 and a second jaw or anvil 22. Thestaple cartridge 21 and the anvil 22 may be brought into closecooperative alignment with one another so the jaws 21, 22 form a clamptherebetween. The jaws 21, 22 may be a first and second jaw that openand close or may be another clamping type structure as is known in theart. The jaws 21, 22 are defined by a staple cartridge 21 locatedtherein. The staple cartridge 21 may be located at the distal end of thehousing 20, in the jaws 21, 22 themselves or may be located in otherlocations as described in U.S. Pat. No. 7,044,353 to Mastri, et al.which is herein incorporated by reference in its entirety. The staplecartridge 21 has one or a number of rows of staples. The surgicalstapler 10 also has an anvil (not shown) and further may include anoptional knife (not shown) as is well known in the art for accomplishingthe stapling. It is appreciated that the closing of the jaws 21, 22 withthe staple cartridge 21 and the anvil 22 may be accomplished by pivotingthe anvil 22 relative to the staple cartridge 21, or by pivoting thestaple cartridge 21 relative to the anvil 22, or by pivoting both thestaple cartridge 21 and the anvil 22.

Generally, actuating the operating portion of the fastening assembly 18is accomplished via intermediate components disposed on or within thenarrow longitudinally extending tubular portion 16. In one non-limitingembodiment, a cylindrical tubular sleeve member surrounds the portion16. The sleeve may be manipulated in a direction with the longitudinalaxis of the surgical stapling device. The sleeve slides onto the anvil22 for closing the jaws 21, 22 that are biased open by a biasing device(not shown) to accomplish the clamping. The surgical stapler 10 of thepresent disclosure has three basic actions or functions, however, thepresent disclosure is intended to be used with any surgical staplerincluding but not limited to surgical staplers having simultaneousclamping (i.e., clamping and firing the stapler at the same time) andindependent clamping (i.e., clamping prior to the staple firing).

First, portion 16 is introduced into the human or animal body and ispositioned with the jaws 21, 22 aligned at the desired stapling site toreceive the target tissue. This may involve rotation of the portion 16relative to the body, either by rotating the surgical stapler 10 as awhole, by rotating simply the portion 16 relative to the frame 12 aspermitted, or a combination of both actions. Thereafter (i.e.,secondly), the surgical stapler 10 secures the target body tissuebetween the staple cartridge or jaw 21 in the distal portion of thehousing 20 and the anvil 22. This is accomplished by a clamping actionof the jaws 21, 22 or alternatively by another similar or differentclamping member.

The jaws 21, 22 are allowed to remain in the closed position for adesired period of time depending on the particular tissue. Byconfiguring the jaws 21, 22 to remain closed for a predetermined periodof time allows any excess liquid or fluid in the tissues to drain out ofthe body tissues prior to actuation of the stapling cartridge 21. Thisensures that the liquid does not traverse out of the tissues afterfiring to form non-uniform staples and instead ensures a proper anduniform staple formation.

With the target tissue clamped between the anvil 22 and the staplecartridge 21, a camming surface which surrounds the housing 20 and anvil22 is employed to close the jaws 21, 22 of the surgical stapler 10 andclamp the tissue between the anvil 22 and the tissue contacting surfaceof the staple cartridge 21. The jaws 21, 22 are clamped by actuation ofa lever 24 opposite the jaws 21, 22 as is known in the art. Thereafter,the surgeon applies the staples to the body tissue. A longitudinallyextending channel is employed to deliver longitudinal motion to an axialdrive member and a tissue cutting knife as is known in the art.

The axial drive member or an axial drive screw contacts pusher elements.The pusher elements drive the staples through the body tissue againstthe fastener or forming surface of the anvil as discussed herein.Typically, in the art the surgical stapler 10 fires usually by anactuation of a first trigger handle or alternatively using a triggerswitch 26. Thereafter, the clamping action of the jaws 21, 22 isreleased and the surgical stapler 10 or a portion thereof may bewithdrawn from the body.

Referring now to FIG. 2, there is shown a block diagram of the surgicalstapler 10 of the present disclosure. According to a first aspect of thepresent disclosure, the surgical stapler 10 may have an optionalcontroller 28. The controller 28 is any electronic device being coupledto a memory for executing one or more readable program instructions oralternatively may be a suitable analog circuit. Still further, thecontroller 28 may be a suitable mechanical member or linkage forcontrolling one or more functions of the surgical stapler 10.

The controller 28 is connected to an internal or external power supplyand a motor and is connected between the anvil 22 and the staplingcartridge 21. In an alternative embodiment, a trigger handle or anotheractuating switch or component 26 is mechanically or electronicallylinked or otherwise connected to the stapling cartridge 21 as is knownin the art as indicated by a dotted line, and the present disclosure isnot intended to be limited to any configuration. Once the staplingcartridge 21 is fired using the trigger switch 26, the jaws 21, 22 areopened and the firing mechanism is retracted. The surgical stapler 10 asa whole may be withdrawn from the body tissue or may be manipulated fora next or second stapling operation as shown.

The present surgical stapler 10 has the controller 28 which is connectedto one of the jaw or anvil 21 or jaw or staple cartridge 21 and thetrigger switch 26 or is connected to both jaws 21, 22 and the triggerswitch 26. In one embodiment, once the desired site is reached, thesurgeon uses the jaws 21, 22 to compress the selected body tissue.Alternatively, the surgical stapler 10 may have a single drive componentthat can actuate both the anvil 22 and stapling cartridge 21.

Thereafter, the controller 28 may provide for a requisite amount ofdelay between clamping and firing (or after clamping and before firing)to ensure tissue compression and expulsion of fluid. After the desiredcompression is reached, the stapling cartridge 21 may be automaticallyengaged by the controller 28 to fire the staples from the staplingcartridge 21 into the body tissue or alternatively the controller 28 maysend a signal to the surgeon thereby informing the surgeon a suggestionthat the surgeon is to fire the staples. It is envisioned that thefiring may be automatic or manual.

Furthermore, the controller 28 may control the speed with which thestaples are fired from the staple cartridge 21. Still further, thecontroller 28 may control an amount of delay before firing. Thecontroller 28 in one embodiment may provide for a predetermined amountof time to elapse prior to outputting a signal to the stapling cartridge21. In another powered stapler embodiment, the controller 28 may slow amotor speed to increase the body tissue compression time.

In still another embodiment, the controller 28 may engage a dampeningdevice 30. The dampening device 30 is configured to slow the actuatingof the staple cartridge 21 in order to increase the overall compressiontime of the body tissue. Such a dampening device 30 may be a hydraulicor a pneumatic type damper or any other device that may dampen ormodulate the operation of one or more components of the surgical stapler10. In another embodiment, the trigger 26 may simply hold the firesignal for a predetermined time period in associated control circuitryand upon the expiration of the predetermined time period may communicatethe signal to the stapling cartridge 21.

The controller 28 may be configured to slow a motor speed, modulate agear or, still further, engage a circuitry of the motor to slow anoperation thereof to otherwise reduce actuation, i.e., a rotation rateof the axial drive screw. Still further, the surgical stapler 10 mayalso include an override switch 32. The override switch 32 is anautomatic or manual device (or other switch) that selectively disengagesthe controller 28 to permit direct actuation of the stapling cartridge21 by the trigger switch 26 without any delay at the surgeon'sdiscretion.

In one aspect of the present disclosure, the present surgical stapler 10includes jaws 21, 22 which compresses tissue between the anvil 130 andthe stapler cartridge 132 of the stapling cartridge 21 (FIG. 2B). Thejaws 21, 22 are understood in the art as a device that allows thesurgeon to manipulate and compress tissue between the anvil 130 and thestaple cartridge 132 prior to urging of the staples 158 from the staplecartridge 132 as shown in FIG. 2B. The jaws 21, 22 may be independentlypowered by a power source such as a motor or pneumatic device, or may bepowered by the same power source as the staple cartridge 21. Thesurgical stapler 10 uses the jaws 21, 22 to clamp tissue between thestapler cartridge 132 and the anvil 130 (FIG. 2b ), then when thestapler 10 is fired the jaws 21, 22 may be tightened further and thenthe staples 158 urged from the stapling cartridge 21.

In one aspect, the surgical stapler 10 may pre-clamp or compress tissueusing the jaws 21, 22 for a first interval. The first time interval maybe preset and fixed, or variable depending on the tissue type. The firsttime interval may be for minutes, seconds or any other variable or fixedpredetermined period of time. Then prior to stapling, the jaws 21, 22may further tighten to further compress the tissue for another secondcompression time interval and then fire. The second time interval may bedifferent from the first time interval and can be shorter or longer thanthe first. In another aspect, the instrument may pre-clamp or compresstissue using the jaws 21, 22 and then simply automatically fire thedevice to urge the staples 158 from the staple cartridge 132 at theconclusion of the first interval. Various configurations are possible,and the present surgical stapler 10 may have program instructions forany number of compression intervals desired by the surgeon and/ordesigner. The surgical stapler 10 may alternatively further use a secondseparate clamping device in association with the stapler 10. It isunderstood that the present disclosure may be incorporated into aninstrument that approximates the tissue before firing such as with a TAsurgical stapler, or can be used with an instrument that requires nosuch approximation before firing such as U.S. Pat. No. 6,817,508 toRacenet, et al. which is herein incorporated by reference in itsentirety.

In another embodiment of the present disclosure, the surgical staplingdevice 10 may provide the surgeon with feedback by virtue of anindicator 36. The indicator 36 may display an amount of compression timeand/or provide feedback of the status of the stapling, or displayinformation relating to the location of the drive screw, or drivemember. In another embodiment of the present disclosure, the surgicalstapler 10 may not have separate clamping and firing actuators andinclude a clamping gradient indicator 36 or simultaneous clamping andfiring indication mechanism. For example, the surgical stapler 10 may beconfigured to allow control of the firing speed which, in turn, controlsthe clamping speed and timing and then provide optimal compression forsqueezing the tissue and pushing the blood and fluid out of the tissueat the desired site.

FIG. 2A shows an exploded view of a number of components of the surgicalstapler 10 of FIG. 1. The stapler 10 has a rack 100 that is slidable inthe handle portion 14. The rack 100 interfaces with a clamp tube 102. Ona distal side of the clamp tube 102 is a channel 104. The channel 104engages with the clamp tube 102 and a pair of forks 106, 108 on a distalside thereof. The stapler 10 also has an upper cover 110 and a lowercover 112, and an extension tube 114. The extension tube 114 engageswith a collar tube 116. The stapler 10 also has a rotation knob 118 witha channel portion 120. The channel portion 120 has a pair of cammingsurfaces 122 on a distal end. The distal end also has a crimp 124 in adistal side to receive the anvil 22.

In operation, the rack 100 slides and moves the clamp tube 102 distally.The clamp tube 102 is provided to interconnect the handle portion 14 andthe extension tube 114. The channel 104 is slidably mounted forreciprocal longitudinal motion. The extension tube 114 provides supportfor the surgical stapler 10 and has slots that interface with the collartube 116. The surgical stapler 10 also has a support 120 forlongitudinal motion and to operate the stapling mechanism as describedin FIG. 2b . The operation of these components is well known and isdisclosed in U.S. Pat. No. 5,318,221 to Green, et al., which is hereinincorporated by reference in its entirety.

Advantageously, the rack 100 moves distally to advance the channel 104in a distal manner. The channel 104 delivers longitudinal motion to apusher cam bar as is known in the art for operation of the staplercartridge 21 shown in FIG. 2b . It should be appreciated that thecomponents shown in FIG. 2a only illustrate one embodiment of thepresent surgical stapler 10, and instead of the rack 100, the surgicalstapler 10 may have a drive screw (not shown) for longitudinal motionand in order to actuate the stapler cartridge 21. Referring now to FIG.2b , there is shown an exploded view of the anvil 22 and the staplercartridge 132 having an actuation sled 169.

Referring to FIG. 2b , the stapler cartridge 21 includes an anvilassembly 130 and a cartridge assembly 132 shown in an exploded view forillustration purposes. The anvil assembly 130 includes anvil portion 22having a plurality of staple deforming concavities (not shown) and acover plate 136 secured to a top surface of anvil portion 134 to definea cavity (not shown). The cover plate 136 prevents pinching of tissueduring clamping and firing of the surgical stapler 10. The cavity isdimensioned to receive a distal end of an axial drive assembly 138.

The anvil 130 has a longitudinal slot 140 that extends through anvilportion 130 to facilitate passage of retention flange 142 of the axialdrive assembly 138 into the anvil slot 140. A camming surface 144 formedon anvil 22 is positioned to engage axial drive assembly 138 tofacilitate clamping of tissue. A pair of pivot members 146 formed onanvil portion 130 is positioned within slots 146′ formed in carrier 148to guide the anvil portion 130 between the open and clamped positions.

The stapler 10 has a pair of stabilizing members 152 engage a respectiveshoulder formed on carrier 148 to prevent anvil portion 30 from slidingaxially relative to staple cartridge 132 as camming surface of the anvil130 is deformed. Cartridge assembly 132 includes the carrier 148 whichdefines an elongated support channel 154. Elongated support channel 154is dimensioned and configured to receive the staple cartridge 132 whichis shown above the carrier 148 in the exploded view of FIG. 2b .Corresponding tabs and slots formed along staple cartridge 132 andelongated support channel 148′ function to retain staple cartridge 132within support channel 154 of carrier 148. A pair of support strutsformed on the staple cartridge 132 are positioned to rest on side wallsof carrier 148 to further stabilize staple cartridge 132 within supportchannel 154, however other arrangements to support the cartridge 132 onthe channel 154 can be used and this arrangement is not limiting.

Staple cartridge 132 includes retention slots 156 for receiving aplurality of fasteners 158 and pushers 160. Longitudinal slots 156extend through staple cartridge 132 to accommodate upstanding cam wedges162 of the actuation sled 164. A central longitudinal slot 166 extendsalong the length of staple cartridge 132 to facilitate passage of aknife blade (not shown). During operation of surgical stapler 10,actuation sled 164 is drive distally to translate through longitudinalslot 156 of staple cartridge 132 and to advance cam wedges 162 distallyand into sequential contact with pushers 160, to cause pushers 160 totranslate vertically within slots 156 and urge fasteners 158 from slots156 into the staple deforming cavities of anvil assembly 130 to effectthe stapling of tissue.

Referring to FIG. 3, the surgical stapler 10 may include indicator 36which may be any device known in the art to provide sensory feedback tothe surgeon. The indicator 36 may be any device that permits a visual,tactile or audible monitoring of one or more conditions of the surgicalstapler 10. The indicator 36 may be disposed on outer surface 34 anddisposed on the handle 14. Alternatively, the indicator 36 may bedisposed on portion 16, on the trigger switch 26, on the lever 24 or inany other suitable location where the indicator 36 may be easily viewedby the surgeon without a change in position of change in footing by thesurgeon.

In one embodiment, as shown the indicator 36 includes a number of lightbulbs 38. The lights 38 may be one light or a series of many lightsbulbs or LEDs with one color or an assortment of two or more colors.Each of the lights 38 may have a color representing one or moreconditions of the surgical stapler 10. Alternatively, one or all of thelights 36 may flash to indicate a condition of the surgical stapler 10.

Upon being actuated by the trigger switch 26, the surgical stapler 10may impart a delay before firing of the staples. However, in order toprovide the proper feedback to the surgeon, the lights 38 provide, forexample, a visual indication of the progress of the firing of thestapling cartridge 21. For example, still referring to FIG. 3, there isshown a first light 40, a second light 42, a third light 44, a fourthlight 46, and a fifth light 48. As the axial drive screw (not shown andin the handle) travels the predetermined drive path the lights 40, 42,44, 46, and 48 illuminate in series to portray the relative distance ofthe drive screw on the exterior of the handle. When the lights 40, 42,44, 46, and 48 are illuminated, the stapling cartridge 21 fires whichensures that proper tissue compression occurs prior to deployment of thestaples.

Referring now to FIG. 4, in another exemplary embodiment of the presentdisclosure, the surgical stapler 10 includes a linear indicator 50having a plurality of discrete segments, first segment 52, secondsegment 54, third segment 56, fourth segment 58, and fifth segment 60.Again, once the trigger switch 26 is actuated to fire the staplingcartridge 21, the segments 52, 54, 56, 58, and 60 each illuminate in apredetermined pattern to indicate to the surgeon the status of theprogression of the drive screw in the handle 14.

Upon all of the segments 52, 54, 56, 58, and 60 being illuminated, thestapling cartridge 21 fires the staple into the body tissue withassurance that an amount of compression time of the body tissue haslapsed. Linear display 50 may have one or more different colors orcombinations of colors to indicate a position of the drive screw such as“red” to indicate firing and “green” to indicate that the firing iscomplete or vice versa. Still further the linear display 50 may displayone or more graphical representations, images, or pictures to indicateone or more conditions or operating parameters of the surgical stapler10.

For example, the linear display 50 may indicate “FIRE” or “COMPLETE”, orany other graphical representation to indicate that surgical stapler 10will fire at the predetermined time period. Various possiblecombinations are possible and all are within the scope of the presentdisclosure.

In still another exemplary embodiment of the present disclosure shown inFIG. 5, the surgical stapler 10 may include a digital display 62. Thedigital display 62 may indicate a count down or count up (or other timeinterval) after actuation of the trigger switch 26. For example, thedigital display 62 may count down to the desired stapling time aftercompression to ensure a predetermined amount of tissue compression bythe jaws 21, 22. The digital display 62 may be activated by the jaws 21,22 being brought in close alignment with one another or activatedindependent of clamping. A desired clamping interval may be preset fordesired tissue.

Alternatively, the digital display 62 may be selectively preset andinput by the surgeon using an input device (not shown). The surgeon mayinput a time period of clamping. Thereafter, the display 62 will suggestfiring at the elapse of the time period, or may automatically to fireafter a predetermined clamping time elapses (e.g., such as from aboutten seconds to forty five seconds) to ensure proper tissue compression.The digital display 62 may be configured to count down from thepredetermined set interval and visually communicate a signal to thecontroller 28. The controller 28 after receiving the signal allows thedesired time period to elapse. After the set time period expires, thecontroller 28 may communicate a second signal to actuate the staplingcartridge 21. Alternatively, the controller 28 may simply modulate thespeed of the motor to commence operation at a speed suitable to actuatethe stapling cartridge 21 at the end of the desired time period. Instill yet another embodiment, the digital display 62 may be configuredto initiate counting after commencement of the clamping of tissue andthen simply display the time from that point onwards to allow thesurgeon to monitor and manually actuate the trigger switch 26 at theexpiration of the desired time period. Thereafter, the digital display62 may simply display or flash the compression time to the surgeon andthe exact amount of elapsed time. It is appreciated that the instrumentmay provide a predetermined delay and then indicate that the instrumentis ready to be manually fired, or alternatively the instrument may delaythen indicate and then automatically fire.

Referring now to FIG. 6, the surgical stapler 10 may alternatively havean analog display 64 disposed on the outer surface of the handle 14which functions similar to the digital display 62. Analog display 64 mayhave an audible alarm or alternatively have a flashing light to indicatethat the appropriate tissue compression time has been reached orexceeded.

Referring now to FIG. 7, there is shown a cross sectional view of thehandle 12 of the surgical stapler along line 7-7 of FIG. 3. In thisembodiment, the surgical stapler 10 is a powered device and has a motor66 with a driving mechanism. The driving mechanism is a drive outputshaft 68. Shaft 68 connects to a first gear 70. The first gear 70 isconnected to a second gear 72 which, in turn, engages an axial drivescrew 74. The motor 66 may be a device that drives one or morecomponents of the surgical stapler 10.

The drive screw 74 is a threaded rod having a number of helical groovesthat are intended to rotate and contact another member to actuate thestapling cartridge 21 in the distal location of the surgical stapler 10once compression is made by the surgeon using the clamp or jaws 21, 22.The axial drive screw 74 is disposed in toothed engagement through acentral bore 76 of the second gear 72. The axial drive screw may also bedisposed offset from the second gear 72 or in any other desired gearedarrangement. Upon actuation of the motor 66, the axial drive screw 74rotates and traverses distally through the portion 16 of the surgicalstapler 10 to engage the stapler cartridge 21 as is well known in theart. Alternatively, the surgical stapler 10 may have a drive piston orplunger instead of the axial drive screw 74 or a single drive mechanismto control both the anvil 22 and the stapling cartridge 21. Suchmechanisms are well known in the art and may be found in U.S. Pat. No.6,330,965 B1 to Milliman, et al., U.S. Pat. No. 6,250,532 B1 to Green,et al., U.S. Pat. No. 6,241,139 B1 to Milliman, et al., U.S. Pat. No.6,109,500 to Alli et al., U.S. Pat. No. 6,202,914 B1 to Geiste, et al.,U.S. Pat. No. 6,032,849 to Mastri, et al. and U.S. Pat. No. 5,954,259 toViola, et al., which are all herein incorporated by reference in theirentirety.

The surgical stapler 10 may include a first switch 80. Switch 80 islocated in a fixed position of the handle as shown. The stapler 10 alsohas a second switch 82 disposed distally relative to the first switch 80that is distal or near the path of the drive screw 74 in the firstinitial position 78. Likewise, the second switch 82 in a second firingposition 84 which is disposed distally from the first initial positionand proximal or near the path of the drive screw 74. Each of the firstand second switches 80, 82 is a limit switch, but alternatively may beany switch known in the art to change or toggle from a first position toa second position by a simple motion of the axial drive screw 74traversing past or adjacent to the respective limit switch.

Once the axial drive screw 74 or a portion thereof traverses past thefirst switch 80, the first switch communicates a signal to thecontroller 28 by lead 86. The controller 28 thus illuminates theindicator 36 or a portion thereof by lead 88 to indicate to the surgeona first location of the axial drive screw 74.

Thereafter, the drive screw 74 or a portion thereof traverses orcontacts the second switch 82 at the second firing position 84. Thesecond switch 82 is also a limit switch and communicates a second signalto the controller 28 by lead 90 of the location or firing of the staplercartridge 21. The controller 28 then illuminates indicator 36 (oranother portion thereof) by lead 88 to indicate to the surgeon that thestapling has been completed. At the conclusion of the stapling, thesurgeon/operator will initiate retraction and then will reverse adirection of the motor 66 by lead 92. The motor 66 then reversesoperation and returns the axial drive screw 74 to the initial position78 for the next stapling operation.

Alternatively, controller 28 upon receiving the first signal from thefirst switch 80 by lead 86 modulates one or more operations of thesurgical stapler 10. For example, in response to receiving of the firstsignal, the controller 28 can control one or more parameters of thesurgical stapler 10 including tissue gap, speed of the motor 66, controlstroke of the axial drive screw 74, axial drive screw travel distance,rotational rate of the axial drive screw and any combinations thereof.

Referring now to FIG. 8, the surgeon may operate/engage the firingmechanism in order to actuate the stapling cartridge 21. The firingmechanism actuates the motor 66 shown in FIG. 8. The axial drive screw74 commences rotation and by traversing past switch 80 the drive screw74 actuates the first switch 80. The first switch 80 outputs the signalto the controller 28 by lead 86. The controller 28 in response to thesignal from the first switch 80 then actuates the first light 40 by lead92. The surgical stapler 10 may further have a suitable structure inorder to engage a stop feature. The stop feature prohibits overdrive ofthe drive screw 74.

Thereafter, after the axial drive screw 74 traverses a predetermineddistance to ensure tissue compression by the clamp or jaws 21, 22. Thesecond switch 82 is actuated and outputs a second signal to thecontroller 28 by lead 90. The controller 28 in response to the secondsignal illuminates the second light 42 by lead 94. The second light 42indicates that the stapling cartridge 21 has fired. The second switch 82may further emit a signal to the controller 28 to reverse or ceasemotion in that direction of the motor 66 or to return the axial drivescrew 74 to the initial position. The physician/operator may alsomanually reverse the direction of the motor 66. A third light 44 mayilluminate to indicate to the surgeon that the axial drive screw 74 isreturning to the initial position 78.

FIG. 8A illustrates another embodiment of the present stapler. In theembodiment shown, the surgeon may operate/engage the firing mechanism inorder to actuate the stapling cartridge 21. However, the first switch80′ is in a different location than the embodiment shown in FIG. 8. Inthis embodiment, the first switch 80′ is located immediately under thelever 24 proximal to handle 14. The switch 80′ in the embodiment of FIG.8A engages a tab 24′ disposed on the lever 24. When the lever 24 isactuated and driven toward the handle 14, the tab 24′ contacts switch80′, and the switch 80′ outputs the signal to the controller 28 by lead86. The controller 28 in response to the signal from the first switch 80then actuates the first light 40 by lead 92.

Thereafter, after the axial drive screw 74 traverses a predetermineddistance to ensure tissue compression by the clamp or jaws 21, 22, thesecond switch 82 is actuated and outputs a second signal to thecontroller 28 by lead 90. Again, the controller 28 in response to thesecond signal illuminates the second light 42 by lead 94. The secondlight 42 indicates that the stapling cartridge 21 has fired. The secondswitch 82 that is actuated by switch 80′ may further emit a signal tothe controller 28 to reverse or cease motion in that direction of themotor 66 or to return the axial drive screw 74 to the initial position.A third indicator 44 may be included to indicate to the surgeon that theaxial drive screw 74 is returning to the initial position 78.

FIG. 8B shows still another embodiment wherein the first switch 80″ islocated at still another location of the handle 14, and on an oppositedistal side of the lever 24 in proximity to pivot. Variousconfigurations are possible and within the scope of the presentdisclosure, and switch 80″ may be placed in various configurationsrelative to the lever 24.

FIG. 9 shows the surgical stapler 10 with a lever 24. The lever 24,shown in the elevated position, controls the clamp or jaws 21, 22,however this arrangement is not limiting and another driving member maycontrol the clamp or jaws 21, 22 such as the motor 66 (FIG. 7). Thelever 24 opens and closes the jaws 21, 22 of the clamp to compress thebody tissue prior to surgical stapling. The surgical stapler 10 furtherincludes an electrical contact 96 with an electrically conductive memberto complete a suitable analog or digital circuit. The electrical contact96 is in a complementary nesting location of the lever 24 when the leveris in a lowered position or mating with the handle 14. When the lever 24is lowered from an elevated or raised position to the lowered positionor contacting the handle 14, the lever 24 engages the electrical contact96. The electrical contact may complete a suitable timer circuit of thedisplay 62 when in the lowered position. In this embodiment, theelectrical contact 96 commences the display 62. The display 62 may countupwards from zero to a predetermined time limit, or may count down froman ideal predetermined tissue compression time interval. Once thedisplayed time reaches the predetermined time interval, an audible alarm98 may sound. The audible alarm 98 provides the surgeon with a cue thatthe optimal tissue compression time has been reached, and that thefiring mechanism should be actuated in order to fire the staple from thestaple cartridge 21 to ensure a uniform staple formation.

FIG. 10 illustrates in still another embodiment where the clamp formedby jaws 21, 22 is actuated by lowering the lever 24. Contemporaneously,the timer circuit of the display 62 is activated by the electricalcontact 96 on the lever 24. The indicator 36 may be the linear display50 which indicates a first color to prompt for the actuation of thestapling mechanism 21 by the trigger switch or button 26. The display 50may then display a second image or illuminate the number of segmentscorresponding to a travel path of the axial drive screw 74 as shown inFIG. 7. Upon actuation, the second switch 82 outputs a signal to thecontroller 28. The controller 28 then stops the motor 66, and thecontroller outputs a control signal to the display 50 to modulate thedisplay from the first color to another second color or from a firstimage to a second image to indicate that the stapling cartridge 21 hasfired. Optionally, the controller 28 may further sound the audible alarm98 indicating that the stapling cartridge 21 has fired. The alarm may beany sound or audible pattern, including a buzzer, a song, a chirp, achime or any combinations thereof. Various indicator configurations arepossible and within the scope of the present disclosure.

In still another embodiment, the jaws 21, 22 may be actuated by loweringthe lever 24. Contemporaneously, the timer circuit of the display 62 isactivated by the lever 24. Thereafter, the indicator 36 indicates afirst indication to prompt for an actuation of the stapling cartridge 21by actuating switch 26 after a desired time period elapses. Once thetrigger switch 26 is actuated, the controller 28 activates the motor 30.The motor 30 then moves the drive screw 74 as shown in FIG. 7.

As the axial drive screw 74 moves in an axial manner, the drive screw(or another plunger 100 connected thereto as shown in FIG. 11) contactsa second member 102. Second member 102 may be any member that modulatesbased on the motion of the plunger 100 and that can be detected orsensed by another device to provide an indication to the surgeon. Thesecond member 102 may be a resistor strip which changes a resistancealong a travel surface 104 of the plunger 100 as the plunger 100 or theaxial drive screw 74 traverses along the portion 16 of the surgicalstapler 10 (or other suitable travel surface location). The resistorstrip 102 is coupled to indicator 36 such that the change in resistanceof the resistor strip 102 selectively illuminates each of the lights 40through 48 to signal an amount of travel by the axial drive screw 74 orthe plunger 100 or other suitable drive member.

Alternatively, the resistor strip 102 may be coupled to anotherindicator 36 such as a linear display 50. The display 50 may illuminatethe number of segments 52, 54, 56, 58, and 60 corresponding to a travelof the axial drive screw 74 or the plunger 100 until the axial drivescrew actuates the stapler cartridge 21. Upon actuated, the resistorstrip 102 outputs a signal to the controller 28 which modulates theoperation of the motor 66, and sends another second signal to thedisplay 50 to indicate that the stapling cartridge 21 has fired. Thedisplay 50 in response thereto may then display a suitable graphicalimage, another color, a textual message, or any other indication toindicate to the surgeon that the firing of the stapling cartridge 21 hasconcluded. Various indicator configurations are possible and within thescope of the present disclosure.

Referring now to FIG. 12, in yet another embodiment of the presentdisclosure, the surgical stapler 10 may further include a non-contactsensor 106. The non-contact sensor 106 may optionally be a so-called“Hall effect non-contact sensor” (or alternatively any other non-contactsensor) that is based in part on the physical principle of the Halleffect named after its discoverer E. H. Hall.

For example, end 108 of the axial screw 74 is directly connected, gearedto, or offset from the motor 74, and a cap like free end 110 of axialscrew 74 contacts the stapler cartridge 21 to actuate the staplercartridge and to fire the staple as discussed previously. The free end110 of the drive screw 74 has a magnetic member 112 which connectsthereto and which will not become dislodged by a rotation of the drivescrew 74. Alternatively, the magnetic member 112 may be disc shaped andsimply connect to the free end 110. In one initial orientation, free end110 and the magnetic member 112 are disposed closely adjacent, or nearto the non-contact sensor 106. At this initial orientation, the magneticmember 112 is separated by a first distance “d” from the non-contactsensor 106.

Once the trigger switch or button 26 is actuated, the motor 66 isactuated, and rotates, the drive axial screw 74 to traverse distally toactuate the stapler cartridge 21 as described above. In the secondorientation after the motor 66 has been actuated, the magnetic member112 moves and is a second distance “d” away from the non-contact sensor106. The second distance is any distance greater than the first distance“d”. As the magnetic member 112 moves away from the non-contact sensor106, the non-contact sensor now located the second distance away fromthe magnetic field of the magnetic member 112 modulates an operation ofthe motor 66.

The term “modulation” is defined as modulating amount of voltagereceived by the motor 66 in a dynamic manner, turning the motor “off” ata desired stroke, changing the motor speed, drive gear reduction of themotor, reduction of the axial drive screw pitch, or a change in thevoltage or the current input of the motor, or changing another firingcomponent, a change of the motor components and any combinationsthereof. This may thereby slow the operation of the motor 66 to increasean amount of compression time of the body tissues between jaws 21, 22.In another alternative embodiment, the magnetic member 112 may bedisposed on a suitable drive piston instead of the drive screw 66. Asthe drive piston travels away from the non-contact sensor 106, a reducedor modulated amount of voltage may be provided to the motor 66. Stillfurther in another alternative embodiment, the non-contact sensor 106may be placed at the free end 110 of the drive screw 74 and the magneticmember 112 fixed.

In another embodiment of the present disclosure, the surgical staplermay have a combined drive mechanism. The combined drive mechanism maycontrol both a firing component of the stapling mechanism and a clampingmechanism. The surgical stapler 10 may, upon being actuated, has thedrive mechanism advance to commence the clamping using the clampingmechanism and then hold and wait thus providing a predetermined delay.The surgical stapler 10 would then provide an indication to thesurgeon/operator once a desired amount of compression is reached.Thereafter, the surgeon/operator would then actuate the drive mechanismafter the time delay. The drive mechanism would then fire the staplesfrom the stapling cartridge 21 into the compressed tissues and thusensure a uniform staple formation. The surgical stapler 10 thus providesa time delay prior to stapling to ensure tissue compression.

Although being shown as an endoscopic surgical stapler, the presentdrive system may be used with any surgical stapling device known in theart, such as endoscopic surgical stapling devices, a pulmonary staplingdevice, a GIA surgical stapling devices, an endo-GIA stapling device, aTA surgical stapling device and any other stapler device for surgeryknow in the art. The present disclosure may also be used with a singledrive surgical stapler that drives both the clamp and the staplingdevice. The present disclosure may be incorporated into a device thatapproximates and then fires such as with a TA surgical stapling deviceor with a surgical stapler without any such approximation of tissue.

Another embodiment of the stapler 10 is shown in FIG. 13. The stapler 10includes a motor 200, which may be substantially similar to the motor 66described above. The motor 200 may be any electrical motor configured toactuate one or more drives (e.g., axial drive screw 74 of FIG. 12). Themotor 200 is coupled to a power source 202, which may be a DC battery(e.g., rechargeable lead-based, nickel-based, lithium-ion based, batteryetc.), an AC/DC transformer, or any other power source suitable forproviding electrical energy to the motor 200.

The power source 202 and the motor 200 are coupled to a motor drivercircuit 204 which controls the operation of the motor 200 including theflow of electrical energy from the power source 202 to the motor 200.The driver circuit 204 includes a plurality of sensors 204 a, 204 b, . .. 204 n configured to measure operational state of the motor 200 and thepower source 202. The sensors 204 a-n may include voltage sensors,current sensors, temperature sensors, telemetry sensors, opticalsensors, and combinations thereof. The sensors 204 a-204 n may measurevoltage, current, and other electrical properties of the electricalenergy supplied by the power source 202. The sensors 204 a-204 n mayalso measure rotational speed as revolutions per minute (RPM), torque,temperature, current draw, and other properties of the motor 200. RPMmay be determined by measuring the rotation of the motor 200. Positionof various drive shafts (e.g., axial drive screw 74 of FIG. 12) may bedetermined by using various linear sensors disposed in or in proximityto the shafts or extrapolated from the RPM measurements. In embodiments,torque may be calculated based on the regulated current draw of themotor 200 at a constant RPM.

The driver circuit 204 is also coupled to a controller 206, which may beany suitable logic control circuit adapted to perform the calculationsand/or operate according to a set of instructions described in furtherdetail below. The controller 206 may include a central processing unitoperably connected to a memory which may include transitory type memory(e.g., RAM) and/or non-transitory type memory (e.g., flash media, diskmedia, etc.). The controller 206 includes a plurality of inputs andoutputs for interfacing with the driver circuit 204. In particular, thecontroller 206 receives measured sensor signals from the driver circuit204 regarding operational status of the motor 200 and the power source202 and, in turn, outputs control signals to the driver circuit 204 tocontrol the operation of the motor 200 based on the sensor readings andspecific algorithm instructions, which are discussed in more detailbelow with respect to FIG. 14. The controller 206 is also configured toaccept a plurality of user inputs from a user interface (e.g., switches,buttons, touch screen, etc.).

The present disclosure provides for an apparatus and method forcontrolling the stapler 10 or any other powered surgical instrument,including, but not limited to, linear powered staplers, circular orarcuate powered staplers, graspers, electrosurgical sealing forceps,rotary tissue blending devices, and the like. In particular, torque,RPM, position, and acceleration of drive shafts of the stapler 10 can becorrelated to motor characteristics (e.g., current draw). The presentdisclosure also provides a feedback system and method for controllingthe stapler 10 based on external operating conditions such as firingdifficulty encountered by the stapler 10 due to tissue thickness.

The sensor information from the sensors 204 a-n is used by thecontroller 206 to alter operating characteristics of the stapler 10and/or notify users of specific operational conditions. In embodiments,the controller 206 controls (e.g., limits) the current supplied to themotor 200 to control the operation of the stapler 10.

FIG. 14 shows a method according to the present disclosure forcontrolling the stapler 10, namely, the motor 200. The method may beimplemented as software instructions (e.g., algorithm) stored in thecontroller 206. In step 302, the controller 206 sets the currentsupplied to the motor 200 to a first current limit value “A.” This maybe done manually or automatically, e.g., preloaded from a look-up tablestored in memory. The controller 206 also stores first upper and lowerRPM limit values “X” and “Y,” respectively, associated with the firstcurrent limit value “A.” In step 304, the controller 206 commencesoperation of the stapler 10 by signaling the motor 200 to rotate thedrive screw 74 to clamp tissue and drive staples therethrough. Thecontroller 206 signals the drive circuit 204 to drive the motor 200 atthe upper RPM limit value “X.”

In step 306, the drive circuit 204 continually monitors RPM of the motor200 and provides the measurement signals to the controller 206. Thecontroller 206 compares the measured RPM signals to the lower RPM limitvalue “Y.” If the value is above the lower RPM limit value “Y” then thedrive circuit 204 continues to drive the motor 200 at the upper RPMlimit value “X.” If the value is below the lower RPM limit “Y,” whichdenotes that the motor 200 has encountered resistance during firing,e.g., thicker tissue, an obstruction, etc., then in step 308 thecontroller 206 sets the current supplied to the motor 200 to a secondcurrent limit value “B.”

The controller 206 also stores second upper and lower RPM limit values“Z” and “W,” respectively, for the second current limit value “B.” Thesecond current limit value “B” is higher than the first current limitvalue “A” since higher current increases the torque and RPM of the motor200 to overcome the resistance encountered during stapling. In step 310,the controller 206 drives the motor 200 at the upper RPM limit value“Z.”

In step 312, the drive circuit 204 continually monitors RPM of the motor200 and provides the measurement signals to the controller 206. Thecontroller 206 compares the measured RPM signals to the lower RPM limitvalue “W.” If the value is above the lower RPM limit value “W” then thedrive circuit 204 continues to drive the motor 200 at the upper RPMlimit value “Z.” If the value is below the lower RPM limit value “W,”which denotes that the motor 200 has encountered further resistanceduring firing, then in step 314 the controller 206 terminates currentbeing supplied to the motor 200. The second current limit value “B” actsas a final current value at which the motor 200 may be operated.

In embodiments, multiple current limit values may be set for the motor200 and the drive circuit 204 to allow the controller 206 to switchbetween multiple current limit values based on the encounteredresistances. Each of the current limit values may also be associatedwith corresponding upper and lower RPM limit values at which thecontroller 206 switches to a neighboring current limit value. In furtherembodiments, the method may switch back to a lower current limit valueif the encountered resistance has lowered, which may be detected basedon a lower current draw and/or higher RPM limit values.

FIGS. 15-17 illustrate performance plots of the motor 200 during variousoperational situations. FIGS. 15-17 show plots of rotational speed,torque, and current as a function of time. In FIGS. 15-17, horizontalaxis 400 represents reference time expressed as a unitless scale, leftvertical axis 402 represents mechanical resistance on the motor 200(e.g., torque) and RPM of the motor 200, which are not proportional, andright vertical axis 404 represents the current supplied to the motor200. The left vertical axis 402 includes first upper and lower RPM limitvalues “X” and “Y,” respectively, and second upper and lower RPM limitvalues “Z” and “W.” The right vertical axis 404 includes first andsecond current limit values “A” and “B.”

FIGS. 15-17 illustrate various embodiments of the method of FIG. 14.FIG. 15 shows an RPM plot 500, a torque plot 502, and a current plot504. As the firing process commences, the mechanical load on the motor200 remains low and the RPM of the motor 200 are held constant at thefirst upper RPM limit value “X” as shown by the plot 500. The methoddoes not progress beyond the step 306 since the RPMs did not drop belowthe lower RPM limit value “Y.” Consequently, the first current limitvalue “A” is not reached during the firing process as represented by theplot 504 and the torque is also held constant as shown by the plot 502.

FIG. 16 shows an RPM plot 600, a torque plot 602, and a current plot604. As the firing process commences, the mechanical load is initiallyconstant as illustrated in FIG. 15 but increased strain on the motor 200is illustrated at a point 606 of FIG. 16. As the load is increasing, themotor 200 requires more current to maintain the RPM at the upper RPMlimit value “X.” The controller 206 signals the drive circuit 204 tolimit the current below the current limit value “A.”

Increase in the mechanical load results in the RPMs of the motor 200dropping below the lower RPM limit value “Y” and the current exceedingthe first current limit value “A” at a point 608 as represented by theplot 600. With reference to the flow chart of FIG. 14, at step 306 ofthe method, the drop in RPMs of the motor 200 is detected and the highercurrent limit value “B” along with upper and lower RPM limit values “Z”and “W” are set in steps 308 and 310, as described above. At a point610, once the higher current limit value “B” is set, the motor 200continues its operation at the upper RPM limit value “Z” until thefiring process is complete.

FIG. 17 illustrates an RPM plot 700, a torque plot 702, and a currentplot 704. As the firing process commences, the mechanical load isinitially constant as illustrated in FIGS. 15 and 16 but increasedstrain on the motor 200 is illustrated at a point 706. As the load isincreasing, the motor 200 requires more current to maintain the RPM atthe upper RPM limit value “X.” The controller 206 signals the drivecircuit 204 to limit the current below the current limit value “A.”

Increase in the mechanical load results in the RPMs of the motor 200dropping below the lower RPM limit value “Y” at a point 708 asrepresented by the plot 700. With reference to the flow chart of FIG.14, at step 306 of the method, the drop in RPMs of the motor 200 isdetected and the higher current limit value “B” along with upper andlower RPM limit values “Z” and “W” are set in steps 308 and 310, asdescribed above.

At a point 710, once the higher current limit value “B” is set, themotor 200 continues its operation at the upper RPM limit value “Z” inresponse to the higher mechanical load until a point 712, at which themotor 200 encounters additional resistance or strain. As the load isincreasing, the motor 200 requires more current to maintain the RPM atthe upper RPM limit value “Z.” The controller 206 signals the drivecircuit 204 to limit the current below the current limit value “B.”

Further increase in the mechanical load results in the RPMs of the motor200 dropping below the lower RPM limit value “W” and the currentexceeding the second current limit value “B” at a point 712 asrepresented by the plot 700. With reference to the flow chart of FIG.14, at step 312 of the method, the second drop in RPMs of the motor 200is detected and the controller 206 signals the driver circuit 204 toshut off the motor 200 at a point 714, as seen in FIG. 17.

The present disclosure provides several advantages to deviceperformance, safety, and to the end users experience. The stapler 10provides an intuitive feedback method to users during operationincluding visual and audible feedback. In particular, the presentdisclosure lowers the RPM of the motor 200 or shuts the motor 200 as thestapler 10 encounters increased mechanical load. This basic performancefeedback fulfills a larger user need which was unaddressed byconventional powered devices. Its implementation allows users to moreeffectively use powered instruments.

Use of this algorithm to selectively and intelligently alter operationalspeeds can offer further benefits. In embodiments, the stapler 10 maydecrease firing speed under excessive conditions. This slowing causesfirings to take longer to complete. As a result additional time isprovided in which tissues can compress and fluids can disperse. Thisallows reloads to be fired successfully onto a larger tissue masses thanwould be possible with a static firing speed stapler. Specific changesto RPM and current limit values in specific situations can reduce devicefatigue, improve staple formation, lower internal temperatures,eliminate the need for duty cycles, increase devices functionallifetime, and reliability.

In addition to basic feedback about device performance this disclosurealso provides a method for a powered devices to detect and discern otherexternal factors, e.g., thicker tissue, which previously were difficultto detect. As a result, improved cutoffs and values for limits can beimplemented, greatly improving the safety of powered devices in use.Using the feedback mechanisms discussed above, users may makeintelligent decisions about what settings and techniques should be usedwhen operating the stapler 10. This intelligence can range from choosinga different reload to fire with a linear stapler, deciding to fire at adifferent articulation angle, to choosing to use a completely differentsurgical technique.

It should be understood that the foregoing description is onlyillustrative of the present disclosure. Various alternatives andmodifications can be devised by those skilled in the art withoutdeparting from the disclosure. Accordingly, the present disclosure isintended to embrace all such alternatives, modifications and variances.The embodiments described with reference to the attached drawing figuresare presented only to demonstrate certain examples of the disclosure.Other elements, steps, methods and techniques that are insubstantiallydifferent from those described above and/or in the appended claims arealso intended to be within the scope of the disclosure.

What is claimed is:
 1. A surgical stapler, comprising: a handleassembly; a clamping device having a staple cartridge containing aplurality of staples and an anvil to compress tissue therebetween; adrive assembly at least partially located within the handle andconnected to the clamping device; a motor operatively coupled to thedrive assembly, the motor variably operable between a first upper andlower rotational speed value and a second upper and lower rotationalspeed value; and a controller operatively coupled to the motor, thecontroller configured to control supply of electrical current to themotor based on a rotational speed of the motor at a first current levelor a second current level, wherein when the motor operates between thefirst upper and lower rotational speed values the controller controlsthe supply of electrical current to the motor at the first currentlevel, and when the motor operates between the second upper and lowerrotational speed values the controller controls the supply of electricalcurrent to the motor at the second current level.
 2. The surgicalstapler according to claim 1, wherein the second upper and lowerrotational speed values are lower than the first upper and lowerrotational speed values.
 3. The surgical stapler according to claim 1,wherein the first current level is lower than the second current level.4. The surgical stapler according to claim 1, further comprising adriver circuit coupled to the motor and the controller, the drivercircuit configured to measure the rotational speed of the motor.
 5. Thesurgical stapler according to claim 4, wherein the controller is furtherconfigured to supply electrical current to the motor at the secondcurrent level in response to the rotational speed of the motor beinglower than the first lower rotational speed value.
 6. The surgicalstapler according to claim 5, wherein the controller is furtherconfigured to terminate supply of electrical current in response to therotational speed of the motor being lower than the second lowerrotational speed value.